Inductive coupling is an effect used to transfer electrical energy from one circuit to an adjacent circuit through inductive coils. A variable current on a primary coil is used to create a varying magnetic field, and thus a voltage, in a secondary coil. Wireless charging systems employing inductive coupling are useful for transferring energy from one apparatus to another. Such systems are used for supplying power, charging batteries, and in some cases also for transferring data. Challenges inherent in such systems include providing efficiency in transferring power. Inefficient systems generate excess heat and are limited in their maximum power transfer capability. Charging of common electronic apparatus, such as 3D glasses, toys, remote controls and other portable rechargeable electronics traditionally has required wired plugs to be inserted into the apparatus as a source of power for the charging of batteries. Techniques using inductive resonance can transmit power, but are limited in their utility, in part by the geometry of charging systems known in the art. Known inductive resonance systems are designed to transmit signals from point-to-point in a generally co-planar orientation, or between members of parallel-plane coil pairs. Moreover, wireless charging systems typically are capable of charging only one device at a time.
Due to these and other problems and potential problems, improved coupled inductor systems for wireless power transmittal would be useful and advantageous contributions to the arts. In particular, apparatus capable of charging two or more devices simultaneously, and in different orientations, e.g., not necessarily co-planar point-to-point, would be a useful and advantageous contribution to the art.